CYP1A2 and benign essential blepharospasm: While, non-constantly, both the ADORA2A rs5760423 and CYP1A2 rs762551 variants have been associated with PD [23,24,25], CYP1A2 rs762551 polymorphism has also been associated with amyotrophic lateral sclerosis and blepharospasm [26,27].